EF: Something really sharp with virtually no wear. The really tough/nebulous ones would be something with very little wear but lousy preservation. Or, like kirispupis brought up, certain specialty types, like this guy: I really couldn't put a grade on it. The coin's half cleaned state obscures some details and the reverse was a mess on day one. However, it's one of the best Sear 805's that I've come across. My grade: really nice for the type and I like it.